At Idle the temp on that chip is about 62 C so you are not that high for operations in games.
You can "Lap" the heatsink and see if that helps bring the temp down a bit! How to Lap a Heatsink
Even though that heatsink/fan may have come as matched to the chip it is probably on the low end for cooling....Change it to a better rated heatsink/fan combo....or replace the fan with a faster one!
Other options would be to make sure there is clean clear airflow throughout the computer. If you built it make sure ALL fans are moving the air in the right direction(be surprised at how many reverse fans so they slow air movement!)
Duct the air from around the chip so that the fan is pulling only cool outside air and not preheated air from within the computer.